The above orthonormality relations for bipolar and tripolar
spherical harmonics can be derived from the orthonormality relations
of Eqs. (REF ) and (REF ) with
the definitions of Eqs. (REF ) and
(REF )In the orthonormality relations for bipolar
and tripolar spherical harmonics presented in
Ref. [1]}, the triangular conditions are
implicit on the right-hand sides..
